Abstract
The cooling effect of turbine vane is of great importance for ensuring thermal protection and economic operation of gas turbines. This study aims to reveal the influence mechanism and performance of impingement cooling and heat transfer within a turbine guide vane cavity. Then, a turbine guide vane cavity with a complex pin fins structure is numerically investigated at a multi-hole impingement by comparison with experiment verification. The results show that the larger the Reynolds number is, the larger the average Nusselt number is on the upper and lower surfaces of the cavity. The average Nusselt number increased on the upper and lower surfaces as the impingement hole diameter increased. Comparing 1 impingement hole with 16 ones, the average Nusselt number of the lower surface of the latter is 553.9% larger than that of the former. Furthermore, the average Nusselt number of the lower surface for pin fin height of 3 mm is only improved by 11.2% for pin fin height of 24 mm. The heat transfer effect near the impingement holes is better than that far away from the impingement holes. In particular, it is recommended to have 14 impingement holes with a hole diameter of 7.2 mm, as well as circular pin fins with a height of 3 mm and spacing of 25.8 mm. In addition, the entropy generation distribution in impingement cooling is analyzed. This study can provide a reference to enhance the turbine vane cooling performance by optimization design.
Highlights
In order to improve thermal efficiency, the gas inlet temperature of a gas turbine is continuously improved
Jet impingement cooling is one of the most effective heat transfer enhancement technology, which is commonly used in gas turbine vane cooling, especially for the pressure side of turbine vane [1]
Yan et al [14] studied the heat transfer of impingement cooling at the leading edge of turbine vane by using transient liquid crystal thermal imaging technology, and found that the Nu and pressure drop increased with the increase in the Re; The biased impingement holes increases the average Nusselt number of the internal surface, reduces the resistance coefficient and significantly improves the heat transfer uniformity
Summary
In order to improve thermal efficiency, the gas inlet temperature of a gas turbine is continuously improved. Xi et al [6] simulated the flow and heat transfer of turbine vane leading edge by array jet impingement cooling, and found that increasing the hole diameter ratio and reducing the hole spacing ratio can effectively improve the comprehensive heat transfer coefficient of vane leading edge impingement cooling. Yan et al [14] studied the heat transfer of impingement cooling at the leading edge of turbine vane by using transient liquid crystal thermal imaging technology, and found that the Nu and pressure drop increased with the increase in the Re; The biased impingement holes increases the average Nusselt number of the internal surface, reduces the resistance coefficient and significantly improves the heat transfer uniformity.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
